首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3465篇
  免费   207篇
  国内免费   10篇
耳鼻咽喉   37篇
儿科学   46篇
妇产科学   70篇
基础医学   466篇
口腔科学   24篇
临床医学   295篇
内科学   1109篇
皮肤病学   69篇
神经病学   261篇
特种医学   69篇
外科学   304篇
综合类   9篇
一般理论   1篇
预防医学   295篇
眼科学   49篇
药学   191篇
中国医学   3篇
肿瘤学   384篇
  2023年   12篇
  2022年   56篇
  2021年   113篇
  2020年   57篇
  2019年   113篇
  2018年   92篇
  2017年   78篇
  2016年   64篇
  2015年   75篇
  2014年   125篇
  2013年   150篇
  2012年   255篇
  2011年   275篇
  2010年   158篇
  2009年   147篇
  2008年   230篇
  2007年   218篇
  2006年   224篇
  2005年   180篇
  2004年   188篇
  2003年   151篇
  2002年   182篇
  2001年   52篇
  2000年   42篇
  1999年   63篇
  1998年   39篇
  1997年   29篇
  1996年   36篇
  1995年   29篇
  1994年   12篇
  1993年   11篇
  1992年   37篇
  1991年   30篇
  1990年   29篇
  1989年   21篇
  1988年   23篇
  1987年   16篇
  1986年   20篇
  1985年   12篇
  1984年   6篇
  1983年   7篇
  1982年   10篇
  1981年   6篇
  1980年   3篇
  1979年   2篇
  1977年   1篇
  1975年   2篇
  1969年   1篇
排序方式: 共有3682条查询结果,搜索用时 31 毫秒
1.
2.
3.
Over 36 million people worldwide are infected with HIV. Antiretroviral therapy (ART) has proven to be highly effective to prevent HIV-1 transmission, clinical progression and death. Despite this success, the number of HIV-1 infected individuals continues increasing and ART should be taken for life. Therefore, there are two main priorities: the development of preventive vaccines to protect from HIV acquisition and achieve an efficient control of HIV infection in the absence of ART (functional cure). In this sense, in the last few years, there has been a broad interest in new and innovative approaches such as mRNA-based vaccines. RNA-based immunogens represent a promising alternative to conventional vaccines because of their high potency, capacity for rapid development and potential for low-cost manufacture and safe administration. Some mRNA-based vaccines platforms against infectious diseases have demonstrated encouraging results in animal models and humans. However, their application is still limited because the instability and inefficient in vivo delivery of mRNA. Immunogens, design, immunogenicity, chemical modifications on the molecule or the vaccine delivery methods are all crucial interventions for improvement. In this review we, will present the current knowledge and challenges in this research field. mRNA vaccines hold great promises as part of a combined strategy, for achieving HIV functional cure.  相似文献   
4.
5.
6.
The use of endogenous Protoporphyrin IX generated through the heme biosynthetic pathway after administration of 5-aminolevulinic acid (ALA) has led to many applications in photodynamic therapy (PDT). In Buenos Aires, Argentina, the Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), reported for the first time, in 1975, porphyrin synthesis from ALA in highly dividing plant tissues. Increased porphyrin synthesis in tumours as well as cell photosensitisation was reported soon after. Our group is also interested in studying the use of new synthetic lipophilic derivatives of ALA as well as ALA delivery in liposomes. We have elucidated the mechanism of ALA transport in mammalian and yeast cells. The interactions between ALA-PDT and nitric oxide were investigated in three murine adenocarcinoma cell lines. In the National University of Río Cuarto, Córdoba, a group is devoted to the synthesis of new porphyrin-derived photosensitisers to study their effects on photoinactivation of bacterial and mammalian cells death by PDT. At the Centre of Electron Microscopy of the Cordoba National University, a prototype of a 630 nm noncoherent light source was designed and constructed. Cost of the light source and scarce knowledge of the benefits of PDT by physicians limit the spread of the treatment throughout the country.  相似文献   
7.
8.
We assessed predictors of spontaneous early neurological recovery after acute ischemic stroke by means of multivariate analysis in a cohort of 1,473 consecutive patients treated at one academic center. At hospital discharge, spontaneous neurological improvement or good outcome was defined as grades 0-2 of the Rankin scale, and poor outcome (no improvement or in-hospital death) as grades 3-5. Spontaneous recovery of neurological deficit at the time of discharge from the hospital was observed in 16% of patients with cerebral infarction (n = 238). Dysarthria-clumsy hand syndrome improved in 44% of patients and was the only variable significantly associated with in-hospital functional recovery in three logistic regression models that in addition to lacunar syndromes, included demographic variables, cardiovascular risk factors, and clinical variables [odds ratio (OR) 2.56], neuroimaging findings (OR 2.48), and outcome data (OR 2.39), respectively. Clinical factors related to severity of infarction available at stroke onset have a predominant influence upon in-hospital outcome and may help clinicians to assess prognosis more accurately. Our work gives a contribution into prognostic factors after acute ischemic stroke. With regard to patterns of stroke, dysarthria-clumsy hand syndrome was a significant predictor of spontaneous in-hospital recovery in ischemic stroke patients.  相似文献   
9.
We evaluated the occurrence of REM sleep behaviour disorder (RBD) and vocal cord abductor paralysis (VCAP) in a group of 9 Machado-Joseph disease (MJD) patients. RBD was diagnosed by clinical history plus audiovisual polysomnography in 4 men and 1 woman (55%). While dreaming, 4 fell out of the bed and the other injured his arms. Laryngoscopy detected bilateral VCAP in 1 patient with stridor who required emergency tracheotomy, and partial vocal cord abductor restriction in 2. RBD and VCAP are two potentially injurious conditions that should be considered part of the clinical spectrum of MJD.  相似文献   
10.
The multimeric structure of von Willebrand factor (vWF) and its ristocetin-induced binding to platelets, using a simple and very sensitive radiomonoclonal antibody-labeled vWF method, was compared in normal plasma, single-donor cryoprecipitate (CP) and five different antihemophilic factor (AHF) concentrates. All the AHF showed a lack of larger vWF multimers, an abnormal 'triplet' pattern, and much lower vWF binding to platelets than that of plasma or CP, vWF being the lowest for those with a lesser proportion of larger vWF multimers. These results suggest that the combination of vWF multimeric analysis and the radiomonoclonal-labeled vWF method may be very useful in the assessment of AHF preparations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号